U.S. patent number 4,386,006 [Application Number 04/700,656] was granted by the patent office on 1983-05-31 for ion-exchange compositions.
This patent grant is currently assigned to The Dow Chemical Company. Invention is credited to Donald F. Harrington.
United States Patent |
4,386,006 |
Harrington |
May 31, 1983 |
Ion-exchange compositions
Abstract
This invention relates to novel ion exchange compositions and to
a method for their manufacture. Ion exchange compositions, wherein
a material having ion exchange capacity is supported on a solid,
water-insoluble, porous substrate, are prepared by contacting a
functional vinyl monomer with such substrate and polymerizing such
monomer therein to bind the polymer to the substrate by
macromolecular entanglement.
Inventors: |
Harrington; Donald F. (Midland,
MI) |
Assignee: |
The Dow Chemical Company
(Midland, MI)
|
Family
ID: |
24814382 |
Appl.
No.: |
04/700,656 |
Filed: |
January 25, 1968 |
Current U.S.
Class: |
521/30; 210/681;
252/180; 502/402; 521/31 |
Current CPC
Class: |
B01J
39/17 (20170101) |
Current International
Class: |
B01J
39/00 (20060101); B01J 39/16 (20060101); C01B
031/16 () |
Field of
Search: |
;252/421,426,427,184,180
;210/24,38R ;521/30 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lechert, Jr.; Stephen J.
Claims
I claim:
1. An ion exchange composition which comprises a solid,
water-insoluble, porous substrate having polymerized within the
pores thereof a vinyl polymer having ion exchange capacity where
the polymer is held within the porous substrate by macromolecular
entanglement.
2. The composition of claim 1 wherein the porous substrate is a
fabric.
3. The composition of claim 1 wherein the porous substrate is
carboxymethylated cotton fabric.
4. The composition of claim 3 wherein the vinyl polymer is selected
from the group consisting of polymers of vinyl benzyl trimethyl
ammonium chloride, vinyl phenyl sulfonic acid, vinyl benzyl
sulfonic acid, and vinyl benzyl iminodiacetic acid.
5. A process for the preparation of an ion exchange composition
which comprises contacting a solid, water-insoluble, porous
substrate with a vinyl monomer capable of polymerization into a
polymer having ion exchange capacity, polymerizing said monomer in
contact with said substrate, and washing from said porous substrate
the polymer which is not attached thereto by macromolecular
entanglement within the pores of said substrate.
6. The process of claim 5 wherein the porous substrate is a
fabric.
7. The process of claim 5 wherein the porous substrate is
carboxymethylated cotton fabric.
8. The process of claim 7 wherein the vinyl monomer is a member
selected from the group consisting of vinyl phenyl sulfonic acid,
vinyl benzyl sulfonic acid, vinyl benzyl iminodiacetic acid and
vinyl benzyl trimethyl ammonium chloride.
Description
This invention relates to novel ion exchange compositions and to
methods for their preparation and more particularly relates to
materials having ion exchange capacity supported on solid,
water-insoluble, porous substrates.
It is an object of this invention to provide novel ion exchange
compositions. A further object is to provide a method for the
preparation of such novel ion exchange compositions. These and
other objects and advantages of the present invention will become
apparent from a reading of the following detailed description.
It has now been discovered that functional vinyl monomers may be
polymerized within a solid, water-insoluble, porous substrate to
produce a composite composition wherein the functional polymer
produced is bound within the porous substrate by macromolecular
entanglement.
Suitable porous substrates include fabrics, paper, porous organic
polymers such as styrene-divinyl-benzene macroporous polymers and
the like, porous inorganic materials such as activated alumina,
silica gel, charcoal, and the like, and cloth and paper modified to
contain ionic functional groups such as phosphorylated or
carboxymethylated cotton. It has been found particularly
advantageous to employ cotton fabrics modified by ionic functional
groups and therefore these materials are usually preferred as the
porous substrates for use in the present invention.
Functional vinyl monomers useful in the process and compositions of
this invention include those functional vinyl aromatic monomers
whose polymers possess ion exchange capacity. For example, vinyl
phenylsulfonic acid, vinyl benzyl sulfonic acid, vinyl benzyl
iminodiacetic acid and the vinyl benzyl quaternary ammonium
compounds such as ##STR1##
In accordance with this invention, the porous substrate is
impregnated with a functional vinyl monomer containing a
polymerization catalyst such that upon heating (e.g., up to about
95.degree. C.) the monomer polymerizes within the substrate and
becomes bound to such substrate by macromolecular entanglement.
After polymerization, the substrate-polymer composite composition
is washed with deionized water to loosen and remove all polymer
which is not intertwined within the porous substrate. The ion
exchange composition produced thereby is then ready for conversion
to the H.sup.+, OH.sup.- or other desired ion form by known methods
and may be used in the same manner and for the same purposes as
other forms of ion exchange materials such as continuous ion
exchange and ion scavenging processes. When the porous substrate is
fabric or paper, it unexpectedly was found that the appearance,
feel and other physical characteristics of the fabric or paper
remain substantially unchanged, yet the composition possesses
excellent ion exchange capacity and therefore makes available a
cloth or paper having significant ion-exchange capacity.
For purposes of greater ion capacity per unit weight, it is usually
desirable to employ a comparatively high proportion of polymer with
the porous substrate, usually up to the saturation point. However,
proportions as low as about 5.0% are also effective to produce
significant ion-exchange capacity.
The following examples are provided to more fully illustrate the
invention but are not to be construed as limiting to the scope
thereof.
EXAMPLE 1
A 4.65 g sample of carboxymethylated cotton lawn was immersed in a
42 weight percent aqueous solution of vinyl benzyl trimethyl
ammonium chloride having a pH of 7 and containing 0.05 weight
percent of Na.sub.2 EDTA as a heavy metal complexing agent and
K.sub.2 S.sub.2 O.sub.8 as a polymerization catalyst. After a
contact time of 5 minutes, the cloth was removed from the solution
and drip dried in air at room temperature. The dry treated cloth
was then placed in an oven in stretched condition and heated to
100.degree. C. for 4.5 hours to cause polymerization of the vinyl
monomer. After heating and polymerization, the fabric was washed to
remove any excess polymer. Upon analysis, the treated cloth product
was found to have a strong base capacity of 0.44 milligrams per
gram but to have retained the appearance and feel of untreated
cloth.
EXAMPLE 2
A 0.829 g sample of carboxymethylated cotton cloth was immersed in
solution containing 6.5 g of sodium styrene sulfonate, 0.005 g of
K.sub.2 S.sub.2 O.sub.8 and 0.0025 g of NaHSO.sub.3 in 17.5 g of
water which had been purged with N.sub.2 for 10 minutes to remove
oxygen from the system. While the cloth was immersed therein, the
solution was heated to 75.degree. C. under a nitrogen atmosphere
overnight. The treated cloth was then removed, washed with
deionized water to remove any polymer not intertwined in the fabric
and converted to the H.sup.+ form using HCl. Upon analysis, the
cloth was found to have a strong acid dry weight ion-exchange
capacity of 0.36 milliequivalents per gram and to have retained the
physical appearance and feel of the original cloth.
EXAMPLE 3
A sample of carboxymethylated cotton lawn cloth was placed in a 90
ml aqueous solution containing 26.5 g of vinyl benzyl iminodiacetic
acid, 0.0197 g of K.sub.2 S.sub.2 O.sub.8 and 0.0098 g of
NaHSO.sub.3. While in contact with the cloth, the mixture was
heated to 75.degree. C. for 24 hours in an atmosphere of nitrogen.
The treated cotton fabric was then removed, washed, scraped and
scrubbed to remove excess polymer and air dried. Analysis showed
the dry weight ion-exchange capacity of the product to be 0.663
milliequivalents H.sup.+ per g and 0.650 milliequivalents Cu.sup.++
per g.
A similar experiment was conducted in the presence of air, without
any NaHSO.sub.3 present and employing heating for 4.5 hours at
100.degree. C. The product had a dry weightion-exchange capacity of
0.472 milliequivalents H.sup.+ per g.
Both products retained the appearance and feel of the original
cloth substrate.
Various modifications can obviously be made within this invention
without departing from the spirit or scope thereof and I therefore
limit myself only as defined in the appended claims.
* * * * *